Interesting... and only $31.42 apparently.
http://www.theregister.co.uk/2016/03/15/wdlabs_pidrive_314gb_capacity/
"Western Digital's WDLabs has spun up a hard disk just for the Raspberry Pi 3.
The “PiDrive” has a capacity of 314Gb is just 7mm tall and looks, per the picture above (here for readers on our mobile site) to boast just a single platter. It's a USB affair, connectivity-wise, but WD says it has tweaked the device so “... the drive's magnetic recording and electrical system operating set-points align with Raspberry Pi's USB data and power design to reduce the electrical power load of the hard drive on Raspberry Pi, while still maintaining sufficient performance to deliver maximum USB data transfer rate.”
..."
Re: WD "PiDrive" ...
Huh, there's also a 1TB drive and various kits too... http://wdlabs.wd.com/products/wd-pidrive-1tb-kit/
Re: WD "PiDrive" ...
1Tb been around for a while, but some cheap codes going for the 314GB I see, could be good for more robust storage without concern for the SD write cycles?
Not tried non-SD root myself, but seems rasbian has support?